1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2007, 2009
4 * Author(s): Hongjie Yang <hongjie@us.ibm.com>,
5 * Heiko Carstens <heiko.carstens@de.ibm.com>
6 */
7
8 #define KMSG_COMPONENT "setup"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11 #include <linux/compiler.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/ctype.h>
16 #include <linux/lockdep.h>
17 #include <linux/extable.h>
18 #include <linux/pfn.h>
19 #include <linux/uaccess.h>
20 #include <linux/kernel.h>
21 #include <asm/diag.h>
22 #include <asm/ebcdic.h>
23 #include <asm/ipl.h>
24 #include <asm/lowcore.h>
25 #include <asm/processor.h>
26 #include <asm/sections.h>
27 #include <asm/setup.h>
28 #include <asm/sysinfo.h>
29 #include <asm/cpcmd.h>
30 #include <asm/sclp.h>
31 #include <asm/facility.h>
32 #include <asm/boot_data.h>
33 #include "entry.h"
34
reset_tod_clock(void)35 static void __init reset_tod_clock(void)
36 {
37 u64 time;
38
39 if (store_tod_clock(&time) == 0)
40 return;
41 /* TOD clock not running. Set the clock to Unix Epoch. */
42 if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
43 disabled_wait();
44
45 memset(tod_clock_base, 0, 16);
46 *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
47 S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
48 }
49
50 /*
51 * Initialize storage key for kernel pages
52 */
init_kernel_storage_key(void)53 static noinline __init void init_kernel_storage_key(void)
54 {
55 #if PAGE_DEFAULT_KEY
56 unsigned long end_pfn, init_pfn;
57
58 end_pfn = PFN_UP(__pa(_end));
59
60 for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
61 page_set_storage_key(init_pfn << PAGE_SHIFT,
62 PAGE_DEFAULT_KEY, 0);
63 #endif
64 }
65
66 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
67
detect_machine_type(void)68 static noinline __init void detect_machine_type(void)
69 {
70 struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
71
72 /* Check current-configuration-level */
73 if (stsi(NULL, 0, 0, 0) <= 2) {
74 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
75 return;
76 }
77 /* Get virtual-machine cpu information. */
78 if (stsi(vmms, 3, 2, 2) || !vmms->count)
79 return;
80
81 /* Detect known hypervisors */
82 if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
83 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
84 else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
85 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
86 }
87
88 /* Remove leading, trailing and double whitespace. */
strim_all(char * str)89 static inline void strim_all(char *str)
90 {
91 char *s;
92
93 s = strim(str);
94 if (s != str)
95 memmove(str, s, strlen(s));
96 while (*str) {
97 if (!isspace(*str++))
98 continue;
99 if (isspace(*str)) {
100 s = skip_spaces(str);
101 memmove(str, s, strlen(s) + 1);
102 }
103 }
104 }
105
setup_arch_string(void)106 static noinline __init void setup_arch_string(void)
107 {
108 struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
109 struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
110 char mstr[80], hvstr[17];
111
112 if (stsi(mach, 1, 1, 1))
113 return;
114 EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
115 EBCASC(mach->type, sizeof(mach->type));
116 EBCASC(mach->model, sizeof(mach->model));
117 EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
118 sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
119 mach->manufacturer, mach->type,
120 mach->model, mach->model_capacity);
121 strim_all(mstr);
122 if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
123 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
124 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
125 strim_all(hvstr);
126 } else {
127 sprintf(hvstr, "%s",
128 MACHINE_IS_LPAR ? "LPAR" :
129 MACHINE_IS_VM ? "z/VM" :
130 MACHINE_IS_KVM ? "KVM" : "unknown");
131 }
132 dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
133 }
134
setup_topology(void)135 static __init void setup_topology(void)
136 {
137 int max_mnest;
138
139 if (!test_facility(11))
140 return;
141 S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
142 for (max_mnest = 6; max_mnest > 1; max_mnest--) {
143 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
144 break;
145 }
146 topology_max_mnest = max_mnest;
147 }
148
early_pgm_check_handler(void)149 static void early_pgm_check_handler(void)
150 {
151 const struct exception_table_entry *fixup;
152 unsigned long cr0, cr0_new;
153 unsigned long addr;
154
155 addr = S390_lowcore.program_old_psw.addr;
156 fixup = s390_search_extables(addr);
157 if (!fixup)
158 disabled_wait();
159 /* Disable low address protection before storing into lowcore. */
160 __ctl_store(cr0, 0, 0);
161 cr0_new = cr0 & ~(1UL << 28);
162 __ctl_load(cr0_new, 0, 0);
163 S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
164 __ctl_load(cr0, 0, 0);
165 }
166
setup_lowcore_early(void)167 static noinline __init void setup_lowcore_early(void)
168 {
169 psw_t psw;
170
171 psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
172 if (IS_ENABLED(CONFIG_KASAN))
173 psw.mask |= PSW_MASK_DAT;
174 psw.addr = (unsigned long) s390_base_ext_handler;
175 S390_lowcore.external_new_psw = psw;
176 psw.addr = (unsigned long) s390_base_pgm_handler;
177 S390_lowcore.program_new_psw = psw;
178 s390_base_pgm_handler_fn = early_pgm_check_handler;
179 S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
180 }
181
setup_facility_list(void)182 static noinline __init void setup_facility_list(void)
183 {
184 memcpy(S390_lowcore.alt_stfle_fac_list,
185 S390_lowcore.stfle_fac_list,
186 sizeof(S390_lowcore.alt_stfle_fac_list));
187 if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
188 __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
189 }
190
detect_diag9c(void)191 static __init void detect_diag9c(void)
192 {
193 unsigned int cpu_address;
194 int rc;
195
196 cpu_address = stap();
197 diag_stat_inc(DIAG_STAT_X09C);
198 asm volatile(
199 " diag %2,0,0x9c\n"
200 "0: la %0,0\n"
201 "1:\n"
202 EX_TABLE(0b,1b)
203 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
204 if (!rc)
205 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
206 }
207
detect_diag44(void)208 static __init void detect_diag44(void)
209 {
210 int rc;
211
212 diag_stat_inc(DIAG_STAT_X044);
213 asm volatile(
214 " diag 0,0,0x44\n"
215 "0: la %0,0\n"
216 "1:\n"
217 EX_TABLE(0b,1b)
218 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
219 if (!rc)
220 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
221 }
222
detect_machine_facilities(void)223 static __init void detect_machine_facilities(void)
224 {
225 if (test_facility(8)) {
226 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
227 __ctl_set_bit(0, 23);
228 }
229 if (test_facility(78))
230 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
231 if (test_facility(3))
232 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
233 if (test_facility(50) && test_facility(73)) {
234 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
235 __ctl_set_bit(0, 55);
236 }
237 if (test_facility(51))
238 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
239 if (test_facility(129)) {
240 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
241 __ctl_set_bit(0, 17);
242 }
243 if (test_facility(130)) {
244 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
245 __ctl_set_bit(0, 20);
246 }
247 if (test_facility(133))
248 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
249 if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
250 /* Enabled signed clock comparator comparisons */
251 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
252 clock_comparator_max = -1ULL >> 1;
253 __ctl_set_bit(0, 53);
254 }
255 if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
256 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
257 /* the control bit is set during PCI initialization */
258 }
259 }
260
save_vector_registers(void)261 static inline void save_vector_registers(void)
262 {
263 #ifdef CONFIG_CRASH_DUMP
264 if (test_facility(129))
265 save_vx_regs(boot_cpu_vector_save_area);
266 #endif
267 }
268
disable_vector_extension(char * str)269 static int __init disable_vector_extension(char *str)
270 {
271 S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
272 __ctl_clear_bit(0, 17);
273 return 0;
274 }
275 early_param("novx", disable_vector_extension);
276
noexec_setup(char * str)277 static int __init noexec_setup(char *str)
278 {
279 bool enabled;
280 int rc;
281
282 rc = kstrtobool(str, &enabled);
283 if (!rc && !enabled) {
284 /* Disable no-execute support */
285 S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
286 __ctl_clear_bit(0, 20);
287 }
288 return rc;
289 }
290 early_param("noexec", noexec_setup);
291
cad_setup(char * str)292 static int __init cad_setup(char *str)
293 {
294 bool enabled;
295 int rc;
296
297 rc = kstrtobool(str, &enabled);
298 if (!rc && enabled && test_facility(128))
299 /* Enable problem state CAD. */
300 __ctl_set_bit(2, 3);
301 return rc;
302 }
303 early_param("cad", cad_setup);
304
305 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
setup_boot_command_line(void)306 static void __init setup_boot_command_line(void)
307 {
308 /* copy arch command line */
309 strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
310 }
311
check_image_bootable(void)312 static void __init check_image_bootable(void)
313 {
314 if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
315 return;
316
317 sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
318 sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
319 sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
320 disabled_wait();
321 }
322
startup_init(void)323 void __init startup_init(void)
324 {
325 reset_tod_clock();
326 check_image_bootable();
327 time_early_init();
328 init_kernel_storage_key();
329 lockdep_off();
330 setup_lowcore_early();
331 setup_facility_list();
332 detect_machine_type();
333 setup_arch_string();
334 setup_boot_command_line();
335 detect_diag9c();
336 detect_diag44();
337 detect_machine_facilities();
338 save_vector_registers();
339 setup_topology();
340 sclp_early_detect();
341 lockdep_on();
342 }
343